#include <cstdio>
using namespace std;
int v[20][20],i,j,s,s1,sf,M,N;
FILE *f,*g;
int main()
{
    f=fopen("flip.in","r");
    fscanf(f,"%i",&N);fscanf(f,"%i",&M);
    for(i=0;i<N;i++)
    for(j=0;j<M;j++)
        fscanf(f,"%i",&v[i][j]);
    fclose(f);
        for(i=0;i<N;i++)
    {   s1=0;
        s=0;
    for(j=0;j<M;j++)
        {
            s=s+v[i][j];
            s1=s1+(-v[i][j]);
        }
        if(s<s1)
            for(j=0;j<M;j++)
                v[i][j]=-v[i][j];
    }
    for(i=0;i<M;i++)
    {   s1=0;
        s=0;
    for(j=0;j<N;j++)
        {
            s=s+v[j][i];
            s1=s1+(-v[j][i]);
        }
        if(s<s1)
            for(j=0;j<N;j++)
                v[j][i]=-v[j][i];
    }

    for(i=0;i<N;i++)
        for(j=0;j<M;j++)
        sf+=v[i][j];
    g=fopen("flip.out","w");
            fprintf(g,"%i ",sf);
    fprintf(g,"\n");
    fclose(g);
return 0;
}